This invention relates to a non-return valve assembly. This is particularly but not exclusively useful for incorporation in an incontinence appliance.
Over the years, there have been numerous attempts to provide incontinence appliances and incontinence devices for use in receiving or conducting away urine from persons afficted with incontinence. In British Pat. No. 910837 published in 1962 there was a proposal whereby a pad could be pumped up by air pressure so that it pressed on a location adjacent the patient's perinium and ischiorectal area in order to close off the patient's bladder outlet. In British Pat. Nos. 1,011,517 and 1,059,680 the use of suction to remove discharged urine through a rubber suction head was proposed. British Pat. No. 1,144,483 published in 1969 and U.S. Pat. No. 3,556,102 published in 1971 are examples of arrangements having a pad or rim surrounding a central hole which leads to a bag for containing discharged urine. There are many other proposals based on this principle. British Pat. No. 1,289,102 published in 1972 discloses the employment of a urine collecting bag having a one-way valve disposed at or adjacent the inlet to the bag; the one-way valve is constituted by a flat tube of moisture impermeable plastics material. The valve has a top opening and a bottom outlet and the latter has a pocketed flap intended to prevent return flow of urine. More recently, proposals have been made for the use of various kinds of pad for wear over the urinary organ.
In British Patent application Ser. No. 2,072,512 the present inventor disclosed a female incontinence device comprising a pad of closed cell resilient impact absorbing polyurethane elastomer which has a central hole. A funnel is in communication with the hole and discharged urine is conducted away by a tube. U.K. Patent application Ser. No. 2,126,099 published March 1984 discloses a female urine collection device having a cup-shaped chamber with a flexible lip on its periphery. A duct leads to a section of flexible tubing. The tubing leads to a collection reservoir and acts as a non-return valve. The receiving chamber and reservoir are mounted in a housing of soft absorbent material. This material is apparently intended to provide external cushioning and the device is disclosed as suitable for receiving involuntary urine discharges. It would not appear to be capable of accommodating substantial volume flows.
U.K. Patent applications Ser. No. 2,135,892 and 3 disclose designs of absorbent pads which may be used as sanitary napkins. U.K. Patent application Ser. No. 2,138,303 and European application Ser. No. 122803 both disclose an incontinence device consisting of a pad of absorbent material incorporating along its upper surface a strip of a skeleton polyester foam material. The function of this is to enable urine to flow rapidly to the surface of those regions of the pad not immediately saturated. In U.S. Pat. No. 4,246,901 the use of a wicking material to absorb urine is disclosed, and a similar concept is present in European Patent application Ser. No. 117351. This suggests that an incontinence pad comprises an absorbent layer with a porous water retardant embossed fibrous sheet overlying the absorbent layer. The product is worn with the embossed sheet adjacent to the wearer and this sheet is intended to reduce fluid strike through to the outer surface of the absorbtive product while allowing the product to breathe.
In European application Ser. No. 93175 the inventor suggests that the use of a resin to absorb urine within a bag by a gelling action.
It will be appreciated that the wearer of an incontinence device can be greatly inconvenienced, and there can be undesired medical problems if the surface of the device can remain damp or have any significant quantity of moisture and this problem is exacerbated by the difficulty of preventing back-flow of discharged urine. In other words, while the prior art is replete with attempts to prevent discharged urine from again contacting the skin of the patient, these attempts have normally been unsuccessful in practice.